1. Field of the Invention
The subject invention relates generally to beverage dispensing containers and more particularly to integral means for venting such containers so that its liquid contents may be extracted by a straw.
2. The Prior Art
Beverage containers made of plastic material are commonly sold and used for the containment of beverages such as juice or soft drinks. Typically, such containers have a lid which covers a top opening through which the container is filled. The lid includes a valve element having an elongate straw stem, a lower body portion which is pivotally captured by the container lid. The valve element has an elongate through bore which aligns with a withdrawal passageway in the lid in a first position, whereby enabling a user to withdraw the liquid contents through the straw stem, and pivots into an unaligned second position to close off the liquid compartment during storage of the container.
The problem attendant such configurations arises from the need to equalize the internal air pressure of the container to withdraw the liquid from the straw stem. Without such equilibrium, the vacuum created within the container by operation of the straw soon shuts off the liquid flow. Therefore, such containers require a self-venting capability in order to operate efficiently.
Commercial beverage containers have utilized various means directed toward achieving self-ventilation. One approach is to create an ancillary second passageway through the valve element which admits air as liquid is extracted from the liquid compartment by the straw stem. A second approach is to use an air vent through the lid which is remote from the valve assembly. The air vent admits air and equalizes air pressure during liquid extraction through the valve element straw.
While such approaches are effective in achieving self-ventilation, certain shortcomings prevent them from achieving a totally satisfactory solution. First, the vent openings represent an avenue by which liquid can escape from the container either as the liquid is withdrawn through the valve element straw or when the container is inverted. Since the subject type of beverage container is usually inverted to some extent when liquid is extracted through the valve element straw, leakage through the vent openings is common and is undesirable to the consumer.
U.S. Pat. No. 5,242,079 teaches a beverage container having the aforementioned separated valve and vent configuration. The valve stem pivots from a flat storage positioned into an upright second position in which the through passage becomes aligned with the lid passageway. The stem element is further provided with a molded bead positioned to penetrate through the vent aperture with the stem in the storage position, to close off the vent as well as retain the stem in the storage configuration.
The patented plug, however, fails to achieve a satisfactory seal in practice. This is because the hard plastic plug to Sealing section interface is not capable of dependably resuming a liquid tight seal every time. Consequently, leakage can occur around the bead and, therefrom, out of the lid.